Western Australian Liberal MP Andrew Hastie was still shadow home affairs minister when he threatened to quit the Coalition's front bench in September last year.

Hastie made it clear that if under-siege opposition leader Sussan Ley did not abandon their party's commitment to net zero greenhouse gas emissions by 2050, he would resign or she would be forced to dump him.

'I've nailed my colours to the mast,' Hastie told ABC Radio Perth's veteran broadcaster Gary Adshead.

Two days later, a Perth grandmother sent an email to dozens of Liberal MPs pleading that they not consider replacing Ley with Hastie, who she said was 'not fit' to be leader.

Sue Roberts-Smith was not moved to write to the MPs over any environmental or economic concerns, but rather the way she perceived Hastie had betrayed her son - Australia's most decorated living soldier and accused war criminal, Ben Roberts-Smith.

Hastie might hold strong views about ensuring the country's energy security, but he appears to have nailed his colours to another mast: helping the campaign to bring down Ben Roberts-Smith.

Mrs Roberts-Smith sent her email to 26 Liberal members of Parliament, including Ley, Angus Taylor, Jane Hume, Michaelia Cash, Andrew Bragg, Alex Hawke and Darren Chester.

Attached to the email, which was headed 'The War Against Corporal Ben Roberts-Smith', was a 39-page dossier containing media references to Hastie going back to 2010.

The dossier included news stories ranging in topic from Hastie's military service to his political ambitions, and his abstention from the parliamentary vote to legalise same-sex marriage in 2017. 

'You should be alarmed at the attachments to this email,' Mrs Roberts-Smith wrote to Hastie's colleagues. 'The document has only a fraction of what harm Andrew has done to the Liberal Party and to others.

'I question his integrity and his motive and so should you.'

A week before Hastie's threat to resign, Ley had sacked his hard-right factional ally Jacinta Nampijinpa Price as shadow defence industry minister.

Price had failed to express support for Ley's leadership or to apologise for claiming the government's immigration policy favoured Indians to help Labor electorally.

'Jacinta Nampijinpa was stood down recently - it is time you had a good hard look at Andrew Hastie,' Mrs Roberts-Smith wrote.

'He has demonstrated in the articles attached that he is not fit to be the leader of the Liberal Party.' 

The email quoted a passage from Sean Thomas Russell's 2007 novel Under Enemy Colours, a naval adventure story set during the French Revolutionary War:  

'For every genius, no matter how small, there is another whose pettiness and jealousy cannot bear it. How many great men have been hounded by others, inferior in every way?'

Before entering politics, 43-year-old Hastie had been a captain in the Special Air Service, the regiment in which Roberts-Smith served when he earned his VC and a Medal for Gallantry.

After being elected to parliament in 2015, Hastie supported the 2016-2020 Brereton Inquiry into war crimes allegedly committed by Australians in Afghanistan, and criticised a toxic 'warrior' culture in special forces. 

Hastie has said little about Roberts-Smith since the father-of-two was charged on April 7 with five counts of murdering unarmed detainees in Afghanistan, but has not always been so reluctant to speak. 

He was assistant minister for defence in March 2022 when he gave evidence against Roberts-Smith in his spectacularly unsuccessful defamation case against Nine newspapers.

Much of Hastie's evidence-in-chief related to a 2012 operation in Afghanistan and brief interactions he had with Roberts-Smith and a junior soldier dubbed Person 66 at the end of that mission.

Under cross-examination, Hastie told the Federal Court he had been hearing various rumours about Roberts-Smith's conduct in Afghanistan since 2013.

He was also revealed as a source of information for journalists Nick McKenzie and Chris Masters, who first accused Roberts-Smith of committing war crimes in a series of stories published by Nine newspapers in 2018.

Asked if he disliked Roberts-Smith, Hastie said: 'I don't dislike Mr Roberts-Smith at all. I pity Mr Roberts-Smith. I pity this whole process. I don't want to be here.'

In her September 17 email to Liberal MPs, Mrs Roberts-Smith said a 'cosy and dangerous relationship' existed between Hastie and the journalists Masters and McKenzie.

'He has done everything he can to assist them with their reckless reports tearing down the Australian Defence Force and our most highly decorated soldier, Ben Roberts-Smith VC MG,' she wrote.

'The gravity of media reporting against Ben Roberts-Smith between 2018 - 2025 has been extreme. 

'Particularly since Andrew Hastie MP, the self-proclaimed whistleblower and witness for Nine Media, has been the source of information to Nick McKenzie and Chris Masters.'

Mrs Roberts-Smith described Hastie's testimony in the defamation case as 'nothing but rumour and gossip'. 

'Hastie has been volunteering the opinion that BRS had wilfully breached the Law of Armed Conflict, intentionally violated the Rules of Engagement (ROE) and knowingly committed war crimes. 

'Hastie finally identified himself in the media in March 2022 and declared himself the whistleblower.'

Mrs Roberts-Smith also stated that in her opinion Hastie 'is the catalyst in the ongoing stories to destroy BRS and other Australians'.

Eleven of the email's recipients were from Hastie's National Right faction: Taylor, Cash, Alex Antic, Blyth Leah, Slade Brockman, Cameron Caldwell, Claire Chandler, Jonathon Duniam, Garth Hamilton, Sarah Henderson and Simon Kennedy. 

The Daily Mail contacted Mrs Roberts-Smith regarding her opinion of Hastie and the dossier she sent to Liberal politicians.

'I love and support my son,' she said, 'and don't wish to comment further.'

Hastie has been contacted for comment. Comment was sought from McKenzie and Masters through Nine. 

Mrs Roberts-Smith is not just a fiercely protective mother of a son accused of being a war criminal. The retired businesswoman was the head of community relations at two large Perth schools and is the matriarch of a distinguished family.

Mrs Roberts-Smith's father Brian Holloway was police commissioner of Papua New Guinea, where she met her future husband when he was the nation's first public prosecutor in the mid-1970s.

Len Roberts-Smith rose through the legal ranks to become a justice of the Supreme Court of Western Australia and judge of the state's Court of Appeal.

The longtime Army Reserve member was later appointed commissioner of the WA Corruption and Crime Commission and served as judge advocate general of the Australian Defence Force with the rank of major general.

The couple's younger son, Sam Roberts-Smith, was an acclaimed operatic baritone who performed with Opera Australia, The Ten Tenors, Deutsche Oper Berlin, Sydney Philharmonia and other companies.

The 40-year-old is a graduate of the famed Western Australian Academy of Performing Arts, which has produced actors Hugh Jackman, Lisa McCune, Marcus Graham, Lucy Durack and William McInnes.

After a 12-year singing career, Sam completed a master’s degree in human resources and joined the Australian Border Force, a sister agency to the Australian Federal Police, which arrested his sibling. 

Both Sam and Ben, who remain close, attended Perth's prestigious Hale School, the alma mater of billionaire Andrew 'Twiggy' Forrest, Perth lord mayor Basil Zempilas, former federal attorney-general Christian Porter, and a host of AFL players.

Hastie's seat, Canning, covers Perth's southern fringes and Mandurah, where he lives. The SAS is based further north at Campbell Barracks in Swanbourne, within the electorate of Curtin.

Hastie, who is considered a potential future Liberal leader, resigned from the opposition frontbench last October after Ley told him he would not be involved in shaping Coalition immigration policy.

The Nationals left the Coalition in late January - the second time they had done so since Peter Dutton's election defeat in May 2025 - and reunited with the Liberals in early February. 

Ley called a leadership spill and was replaced by Angus Taylor on February 13. She resigned from parliament, opening the way for One Nation's David Farley to take her seat of Farrer in May.

Taylor appointed Hastie shadow minister for industry and sovereign capability and at the same time the socially conservative father-of-three became deputy leader of the opposition in the lower house. 

The day Roberts-Smith was charged, former Liberal prime minister Tony Abbott spoke out in his support, saying it was 'wrong to judge the actions of men in mortal combat by the standards of ordinary civilian life'.

Hastie also issued a statement about his former comrade, reiterating he had given evidence against Roberts-Smith in his defamation action 'as required by law'.

'In 2022, I was one of 21 SAS veterans of the war in Afghanistan subpoenaed as a witness in the defamation action brought by Ben Roberts-Smith against Nine Media,' he said.

'As a qualified member of the SAS, I was present on one of the operational missions in 2012 that was examined by the Federal Court.

'I gave testimony under oath, as required by law.'

One of the murder charges faced by 47-year-old Roberts-Smith relates to that 2012 mission and it is possible Hastie will be called as a prosecution witness if the case ever goes to a hearing. 

'I urge every Australian to respect the rule of law, the criminal justice system, and the accused's right to a presumption of innocence and a fair trial,' Hastie said.

'Therefore, I will not prejudice this trial by making any further comment.'

Roberts-Smith, who denies involvement in unlawful killings in Afghanistan and is on bail, is excused from attending when his matter is next mentioned in court in June.